1. Field of the Invention
The present invention relates to a liquid supply device and an image recording apparatus, and more particularly, to a pressure control technique that supplies liquid to a liquid ejection head.
2. Description of the Related Art
To stably supply ink to an ink jet head and to stably operate the ink jet head in an ink jet recording apparatus, pressure of an ink passage and the internal pressure of the ink jet head need to be controlled to be constant.
For this control of pressure, the fluctuation of the pressure of the ink passage and the fluctuation of the internal pressure of the ink jet head are suppressed by a damper provided on the ink passage. The damper includes a liquid chamber that communicates with an ink passage and a gas chamber that is provided so as to face the liquid chamber with an elastic diaphragm interposed therebetween, and a technique for protecting the elastic diaphragm from excessive deformation or damage is known.
For example, JP2008-230137A discloses a technique in which a device for adjusting the back-pressure of a liquid ejection head partitioned into a liquid storage chamber and a gas storage chamber by a movable diaphragm, which can be deformed, is provided with a stopper member for limiting the movable range of the movable diaphragm.
Further, JP2004-74462A discloses an air damper employing a structure in which a reinforcing plate is fixed to the surface of a diaphragm of an ink storage portion to prevent the swelling of the diaphragm.